/* * (C) 2013 Marc Kleine-Budde * * Based on the stm-serial driver: * * (C) Copyright 2010 Juergen Beisert - Pengutronix * * ...also based on the u-boot auart driver: * * (C) 2011 Wolfgang Ocker * * Based on the standard DUART serial driver: * * (C) 2007 Sascha Hauer * * (C) Copyright 2009-2010 Freescale Semiconductor, Inc. * * Further based on the Linux mxs-auart.c driver: * * Freescale STMP37XX/STMP378X Application UART driver * * Author: dmitry pervushin * * Copyright 2008-2010 Freescale Semiconductor, Inc. * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * */ #include #include #include #include #include #include #include #include #include #include #define HW_UARTAPP_CTRL0 (0x00000000) #define HW_UARTAPP_CTRL2 (0x00000020) #define HW_UARTAPP_CTRL2_SET (0x00000024) #define HW_UARTAPP_CTRL2_CLR (0x00000028) #define BM_UARTAPP_CTRL2_CTSEN (0x00008000) #define BM_UARTAPP_CTRL2_RTSEN (0x00004000) #define BM_UARTAPP_CTRL2_RXE (0x00000200) #define BM_UARTAPP_CTRL2_TXE (0x00000100) #define BM_UARTAPP_CTRL2_USE_LCR2 (0x00000040) #define BM_UARTAPP_CTRL2_UARTEN (0x00000001) #define HW_UARTAPP_LINECTRL (0x00000030) #define BM_UARTAPP_LINECTRL_FEN (0x00000010) #define BM_UARTAPP_LINECTRL_BAUD_DIVFRAC (0x00003F00) #define BF_UARTAPP_LINECTRL_BAUD_DIVFRAC(v) \ (((v) << 8) & BM_UARTAPP_LINECTRL_BAUD_DIVFRAC) #define BP_UARTAPP_LINECTRL_BAUD_DIVINT (16) #define BM_UARTAPP_LINECTRL_BAUD_DIVINT (0xFFFF0000) #define BF_UARTAPP_LINECTRL_BAUD_DIVINT(v) \ (((v) << 16) & BM_UARTAPP_LINECTRL_BAUD_DIVINT) #define BP_UARTAPP_LINECTRL_WLEN (5) #define BM_UARTAPP_LINECTRL_WLEN (0x00000060) #define BF_UARTAPP_LINECTRL_WLEN(v) \ (((v) << 5) & BM_UARTAPP_LINECTRL_WLEN) #define HW_UARTAPP_LINECTRL2_SET (0x00000044) #define HW_UARTAPP_INTR (0x00000050) #define HW_UARTAPP_DATA (0x00000060) #define BM_UARTAPP_STAT_RXFE (0x01000000) #define BM_UARTAPP_STAT_TXFE (0x08000000) #define HW_UARTAPP_STAT (0x00000070) #define BM_UARTAPP_STAT_TXFF (0x02000000) struct auart_priv { struct console_device cdev; int baudrate; struct notifier_block notify; void __iomem *base; struct clk *clk; }; static void auart_serial_putc(struct console_device *cdev, char c) { struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev); /* Wait for room in TX FIFO */ while (readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_TXFF) ; writel(c, priv->base + HW_UARTAPP_DATA); } static int auart_serial_tstc(struct console_device *cdev) { struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev); /* Check if RX FIFO is not empty */ return !(readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_RXFE); } static int auart_serial_getc(struct console_device *cdev) { struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev); /* Wait while RX FIFO is empty */ while (!auart_serial_tstc(cdev)) ; return readl(priv->base + HW_UARTAPP_DATA) & 0xff; } static void auart_serial_flush(struct console_device *cdev) { struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev); /* Wait for TX FIFO empty */ while (!(readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_TXFE)) ; } static int auart_serial_setbaudrate(struct console_device *cdev, int new_baudrate) { struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev); uint32_t ctrl2, quot, reg; /* Disable everything */ ctrl2 = readl(priv->base + HW_UARTAPP_CTRL2); writel(0x0, priv->base + HW_UARTAPP_CTRL2); /* Calculate and set baudrate */ quot = (clk_get_rate(priv->clk) * 32) / new_baudrate; reg = BF_UARTAPP_LINECTRL_BAUD_DIVFRAC(quot & 0x3F) | BF_UARTAPP_LINECTRL_BAUD_DIVINT(quot >> 6) | BF_UARTAPP_LINECTRL_WLEN(3) | BM_UARTAPP_LINECTRL_FEN; writel(reg, priv->base + HW_UARTAPP_LINECTRL); /* Re-enable UART */ writel(ctrl2, priv->base + HW_UARTAPP_CTRL2); priv->baudrate = new_baudrate; return 0; } static int auart_clocksource_clock_change(struct notifier_block *nb, unsigned long event, void *data) { struct auart_priv *priv = container_of(nb, struct auart_priv, notify); return auart_serial_setbaudrate(&priv->cdev, priv->baudrate); } static void auart_serial_init_port(struct auart_priv *priv) { stmp_reset_block(priv->base + HW_UARTAPP_CTRL0, 0); /* Disable UART */ writel(0x0, priv->base + HW_UARTAPP_CTRL2); /* Mask interrupts */ writel(0x0, priv->base + HW_UARTAPP_INTR); } static int auart_serial_probe(struct device_d *dev) { struct resource *iores; struct auart_priv *priv; struct console_device *cdev; priv = xzalloc(sizeof *priv); cdev = &priv->cdev; cdev->tstc = auart_serial_tstc; cdev->putc = auart_serial_putc; cdev->getc = auart_serial_getc; cdev->flush = auart_serial_flush; cdev->setbrg = auart_serial_setbaudrate; cdev->dev = dev; dev->priv = priv; iores = dev_request_mem_resource(dev, 0); if (IS_ERR(iores)) return PTR_ERR(iores); priv->base = IOMEM(iores->start); priv->clk = clk_get(dev, NULL); if (IS_ERR(priv->clk)) return PTR_ERR(priv->clk); auart_serial_init_port(priv); /* Disable RTS/CTS, enable Rx, Tx, UART */ writel(BM_UARTAPP_CTRL2_RTSEN | BM_UARTAPP_CTRL2_CTSEN | BM_UARTAPP_CTRL2_USE_LCR2, priv->base + HW_UARTAPP_CTRL2_CLR); writel(BM_UARTAPP_CTRL2_RXE | BM_UARTAPP_CTRL2_TXE | BM_UARTAPP_CTRL2_UARTEN, priv->base + HW_UARTAPP_CTRL2_SET); console_register(cdev); priv->notify.notifier_call = auart_clocksource_clock_change; clock_register_client(&priv->notify); return 0; } static const __maybe_unused struct of_device_id auart_serial_dt_ids[] = { { .compatible = "fsl,imx23-auart", }, { /* sentinel */ } }; static struct driver_d auart_serial_driver = { .name = "auart_serial", .probe = auart_serial_probe, .of_compatible = DRV_OF_COMPAT(auart_serial_dt_ids), }; console_platform_driver(auart_serial_driver);